Annual cycle

Annual cycle

In geosciences, an annual cycle is the part of a measured quantity's fluctuation that is attributed to Earth's changing position in orbit over the course of the year. Such quantities might be influenced directly (e.g. incoming solar radiation at a point at the surface) or indirectly (e.g. stratospheric westerlies and easterlies over the winter and summer hemispheres, respectively) by orbital position.

The annual cycle is commonly estimated from observational data or model output by taking the average of all Januaries, all Februaries, and so forth. If the observational record is long enough and conditions are stationary (i.e. there is no significant long-term trend), a meaningful annual cycle will result that can be used to calculate an anomaly time series.

(Note that grouping data according to the months in the Gregorian calendar makes an implicit assumption that the annual cycle in question is the vernal equinox tropical year followed by that calendar. However, the annual cycle for some phenomena may be a different kind of year; see the seasonal year article for discussion.)


Wikimedia Foundation. 2010.

Игры ⚽ Поможем написать реферат

Look at other dictionaries:

  • Annual growth cycle of grapevines — Grape vine and fruit The annual growth cycle of grapevines is the process that takes place in the vineyard each year, beginning with bud break in the spring and culminating in leaf fall in autumn followed by winter dormancy. From a winemaking… …   Wikipedia

  • cycle — {{Roman}}I.{{/Roman}} noun 1 series of events that happen repeatedly ADJECTIVE ▪ annual, daily, monthly, seasonal, weekly ▪ the annual cycle of church festivals ▪ irregular …   Collocations dictionary

  • cycle — cy‧cle [ˈsaɪkl] noun [countable] a series of events that happen in an order that regularly repeats itself: • Approved Training Practices are monitored by the Association on a five year cycle. ˈbilling ˌcycle ACCOUNTING the usual time that is… …   Financial and business terms

  • Cycle to Work scheme — is a UK Government annual tax exemption initiative introduced in the 1999 Finance Act to promote healthier journeys to work and to reduce environmental pollution. It allows employers to loan cycles and cyclists safety equipment to employees as a… …   Wikipedia

  • cycle counting — cycle count UK US noun [C] ► ACCOUNTING, PRODUCTION, COMMERCE the process of counting a small chosen set of goods and materials owned by a company or available for sale in a store, etc. on each business day rather than having one time of the year …   Financial and business terms

  • cycle count — UK US noun [C] ► ACCOUNTING, PRODUCTION, COMMERCE the process of counting a small chosen set of goods and materials owned by a company or available for sale in a store, etc. on each business day rather than having one time of the year, etc. when… …   Financial and business terms

  • Cycle Friendly Awards — Trophies for the winners of the five categories of the 2009 Cycle Friendly Awards The New Zealand Cycle Friendly Awards were devised by the Cycling Advocates Network (CAN) in 2003. The purpose of the awards is to acknowledge and celebrate some of …   Wikipedia

  • Annual plant — Botanically, an annual plant is a plant that usually germinates, flowers and dies in one year. True annuals will only live longer than a year if they are prevented from setting seed. Some seedless plants can also be considered annuals even though …   Wikipedia

  • annual — annually, adv. /an yooh euhl/, adj. 1. of, for, or pertaining to a year; yearly: annual salary. 2. occurring or returning once a year: an annual celebration. 3. Bot. living only one growing season, as beans or corn. 4. performed or executed… …   Universalium

  • Cycle of poverty — In economics, the cycle of poverty is the set of factors or events by which poverty, once started, is likely to continue unless there is outside intervention. [1] The cycle of poverty has been defined as a phenomenon where poor families become… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”